The Antibacterial Activity of Induced and Non-induced Usherhopper, Poekilocerus bufonius Hemolymph

Aim: Insects secret antimicrobial peptides into the hemolymph to protect themselves against bacterial infection. This study aimed to test the antibacterial activity of the usherhopper, Poekilocerus bufonius hemolymph against positive (two species) and negative (six species) gram bacteria.

Study Design: Non-induced and induced hemolymph (for six and twelve hours) by Escherichia coli were used for this study.

Place of Study and Duration: Department of Biotechnology, Faculty of Science, Taif University, Taif, Saudi Arabia, between March and July 2016.

Methodology: Thirty usherhopper adults were collected from Taif Governorate, Saudi Arabia. 10 insects were used for each treatment and twenty microliter of E. coli was injected into the coelom to stimulate the usherhopper immunity. Hemolymph antibacterial assay was carried out using ten microliter hemolymph on the pieces of filter paper and then the media culture was incubated at 37°C for 24 hours. The formation of inhibition zone represented the antibacterial hemolymph effect in the medium.

Results: It was found that bacteria-induced hemolymph and non-induced hemolymph of usherhopper had an­tibacterial effect against eight species of bacteria. The inhibition zones diameter of tested bacteria species were significantly differed at all treatments of the non-induced, induced for 6 h and induced hemolymph for 12 h. In general, the higher antibacterial activity was recorded against E. coli whether the hemolymph was induced or non-induced. With the exception of three tested bacteria species i.e., Proteus mirabills, Bordetella petrii and Entrobacter hormaechei, the inhibition zone diameter not significantly affected by the non-induced, induced for 6h and induced for 12 h.

Conclusion: Usherhopper immune sys­tem against pathogens can be replacing the natural de­fensive mechanisms against invading microorganisms and can prevent indiscriminate use of chemical agents. We suggest that the extraction and definition of peptides from usherhopper hemolymph could be useful in defensive strategy against the pathogenic bacteria for human, plants and animals.